1. Field of the Invention
The present invention is related to a heat-dissipating module and particularly to heat-dissipating module, in which the fan flow passages provide the area thereof greater than the receiving plane of the radiator.
2. Brief Description of the Related Art
Due to semiconductor industry developing rapidly, the electronic components is developed toward minimization and high frequency and problem of high heat generation is accompanied with high power of the powerful electronic components. The high heat emitted from unit area of the electronic components has become a non-ignorable heat source. If the heat it is not removed, normal operation of the electronic components is influenced with the extremely high temperature thereof and it results in unsteady system. In order to remove excessive heat of the electronic components, providing a cooling system is essential to solve different stages of heat problems.
In order to maximize the function of the electronic components and the machine, sufficient heat dissipation is very important so that factors, which have to be considered during designing a cooling system effectively, are (1) heat amount generated by the component; (2) the space size and weight limitation; (3) temperature in the work environment; (4) the cost of the cooling system; and (5) fluid used with the cooling system. The technology and semi-conductor manufacturing process progress rapidly lead to time pulses of the electronic components and chips being upgraded incessantly. For the ordinary computer, the main heat source is from the microprocessor, north and south bridge chips on the main board, high performance chip on VGA, hard disk, CD drive and power supply. The microprocessor with higher frequency can even emit heat with hundred watts and the heat is equivalent a hot metal plate. It is surprising heat and it is probably more serious in the near future under the condition of fast technology development. Of course, the north and south bridge chips, the hard disk or 3D plotting VGA may increase heat generation to influence the operation performance of the entire system in the future in addition to the microprocessor. Hence, how to find a good cooling method is a very important subject. However, for the problem of heat dissipation, space is a great factor has to be considered. If heat is incapable of moving outward, temperature of the system keeps rising in a high heat system. How to remove heat in a limited space fast and efficiently is a much harder work.
The computer available on the market mostly has limited space so that a small size fan is usually mounted to the cooling fins before the cooling fins are attached to a heat generating part to perform heat dissipation work.
Further, how to promote cooling method and technology and to allow the system effective operation fast are common subjects researched by the industry and academy. The cooling ways currently used have natural convection cooling, forced convection cooling, liquid direct or indirect cooling and phase change cooling.
The most popular cooling way is forced convection cooling because air is an indispensable and easily obtained fluid without the need of cost and power. Generally, a fan associated with radiator as a unit is used for dissipating high heat generation mechanism. The fan acts to drive the air for achieving the purpose of forced convection and the radiator acts to provide high heat conductivity and surface area contacting with the air for intensify the cooling effect. Hence, the radiator is made of good conductivity such as aluminum alloy or steel and the larger the surface area contacting with the air is, the better the cooling effect is.
The fan has advantages such as simple structure, low cost, least damage and less driven energy source so that it is popularly used. For the axial flow fan, the air flow can be guided and blown outward along a direction parallel to the central shaft of the fan blades and the advantages of the axial flow fan has features such as small static pressure and large flow rate such that it is mostly utilized in low resistance location. The fan adopted in the general cooling system, which is less resistance in addition to problem in design, is the axial flow fan because the axial flow fan is suitable for environment with large air and low pressure.
Further, Taiwanese Patent Official Gazette Publication No, 527089 discloses a flow-guiding device of a cooling device and the cooling device itself. The cooling device includes a flow-guiding pipe with a front opening, a rear opening and multiple inner flow-guiding baffles. The front opening provides an area greater than the rear opening and connects with the outlet of a fan. The rear opening is connected to the cooling fins such that the air can move into the guiding pipe via the front opening during the fan rotates and the then the air is guided with the guiding baffles to move outward via the rear opening to remove heat transmitted with cooling fins.
However, problem of the preceding prior art while in use are the fan being far from the heat source and influencing heat dissipating effect due to the guiding device being dispose between the fan and the cooling fins. Further, the height of the guiding device is a distance has to be passed over by the fluid moving outward via the outlet of the fan so that it results in wasting kinetic energy of the fluid. In addition, the fluid at the outlet of the fan is low but temperature of the fluid increases during passing through the guiding pipe so that the fluid at the cooling fins provides temperature higher than that at the outlet of the fan to degrade heat exchange rate between the fluid and the cooling fins. The preceding problems significantly deduct the heat dissipating effect.